Comparative Characteristics of Bandpass Filters Based on WDR and Microstrip Resonators

The article presents the results of comparative analysis of WDR and microstrip-based resonator filters regarding their electrical parameters and overall dimensions. For alternative WDR filters design, we use a method of intellectual synthesis of a band pass filter structure which is based on formalized knowledge about the physics of coupled resonators. The basic idea of the expert system created consists in physical analysis of signals passing through the filter, which is performed on the basis of a known solution for electrodynamic problem of scattering of fundamental electromagnetic waves in a multi-tier structure. The comparative analysis is conducted in a wide frequency range of 3 – 70 GHz. We show that the advantage of WDR filters consists in selective properties and discuss the ways of their adaptation to planar technologies. It was demonstrated that electrodynamic properties of WDR filters allow creating devices ranging from narrow to ultra wide passbands. Finally, it was emphasized that a combination of superconducting materials and sapphire or quartz resonators is also very promising for developing WDR-based filters with unique selective properties.